Process and apparatus for dry spinning artificial silk



Jan 23, 134. E. 6mm. 3 399449299 PROCESS AND APPARATUS FOR DR! SPINNING ARTIFICIAL SILK Filed April 5, 1930 2 Sheets-Sheet l ATTORNEYS Jane 23, 1 .9340 QRIQLH 1,944,29

PROCESS AND APPARATUS FOR DRY SPINNING ARTIFICIAL SILK Filed April 5, 1930 2 Sheets-Sheet 2 INVENTdR Patented Jan. 23, 1934 tears PROCESS AND APPARATUS FOR DRY SPINNING ARTIFICIAL SILK Ernesto Orioli, Milan, Italy, assignor to Ruth- Aldo Company, -Inc., a corporation of New York Application April 5, 1930, Serial No. 442,027, and in Italy November 11, 1929 11 Claims.

This invention relates to a process and apparatus for dry spinning artificial silk, which is often referred to as rayon. filaments are produced in such a manner that ;;the objectionable sparkling efiects of the same are greatly minimized or entirely overcome.

It is well known that in the dry spinning of cellulose esters or ethers elementary filaments are easily obtained having a flat cross-section 1 and smooth edges or in cross-section somewhat like a dumb-bell. Such fiossy filaments in the form of a ribbon produce in yarns special sparkling effectswhich greatly reduce the possibility of employing them. a

To avoid this defect, different proceedings have 7 been proposed, in order to obtain elementary filaments having star-like cross-sections.

I have now found that the cross-section of the collodion jet issuing from the spinning nozzle can be favorably influenced by a hot current of gas and vapors-taken from the spinning cell itself.

In my invention, a pipe may be located in the spinning cell or near the cell. This pipe isopen at both ends and connects the space around the spinning nozzle with the lower part of the cell.

This pipe may be heated internally by an electric heater or by an interior pipe of a smaller diameter in which a heating medium circulates 3f) ,7 or it may be heated externally by a jacket. The inside temperature of the pipe is higher than the average temperature of the spinning cell, so that a rising gas current is produced in theinside of the pipe and. this current strikes the collodion jets issuing out of the spinning nozzle, creating favorable conditions of evaporation of the solvent in order to cause the desirable cross-section of the filaments tobe obtained.

In the application of Raymond A. J. Thenoz, Serial No. 423,166, filed January 24, 1930, there was described a process and apparatus for producing a dull luster rayon by causing a shifting or movement of gases at an angle to the path of the jets adjacent the spinneret before the filaments harden, this shifting or movement of the gases being produced by a fan or the like. By the present invention, a shifting or movement of gases which strike the filaments at an angle is produced by heating the gases in a particular 50 j. way and permitting them to rise.

The invention will be understood from the description in connection with the accompanying drawings, in which Fig. 1 is a vertical section through a spinning cell or chamber; Fig. 2 is a I section along the line 2-2 of Fig. 1; Figs. 3 and By this invention,

5 are vertical sections through modifications of the spinning cell; Figs. 4 and 6 are sections along the line .--4 of Fig. 3 and 6-6 of Fig. 5,

respectively; Fig. 7 is a vertical section showing near the bottom of the cell for the introduction of air or gas to remove the solvent from the filament and leave'a hard filament, and the outlet for the air or gas is shown at 4 near the upper end of the cell. Openings 5 may be provided as indicated, with windows for inspection of the interior of the cell.

A spinneret with its supporting pipe 6 which is of the well known type, is located at the upper end of the cell for extruding or squirting filaments into the cell, and the cone '7 is provided at the bottom for removing the filaments.

A vertically extending pipe B having its lower end open and having an outlet 9 near the top is located in the cell 1 to one side of the center line, so that the outlet 9 will be near the outlet of the spinneret 6. A heating coil 10, which may be an electrical or other sort of heater, is located in the pipe 8, so that the air or gas inside of this pipe will be heated and rise to strike the filaments at an angle as they issue from the spinneret.

In the other modifications, the parts that are common to the embodiment of the cell already described are referred to by the same reference characters and the description will not be repeated.

In the modification shown in Figs. 3 and 4, the vertically extending pipe 11 through which the hot air or gas rises is located outside of the chamber or cell 1 with its lower end 12 extending through the wall of this cell near the bottom. The upper end of the pipe 11 has an outlet 13 also extending through the wall of the cell 1 close to the spinneret 6. The pipe 11 is heated by a smaller pipe 14 extending a portion of the way therethrough with its lower end 15 extending through the side of the pipe 11 and through the wall of the jacket 2, near the lower end thereof. A pipe 16 leads away from the upper end of the jacket. A heating fluid is passed through the pipe 14 for heating the air in the pipe 11 and this heating fluid then passes through the jacket 2 and out through the pipe 16.

In the modification shown in Figs. 5 and 6, the lower end. 18 of the vertically extending pipe 1'? extends some distance into the interior of the chamber 1 and the outlet 19 from the pipe 1'? also extends some distance into this chamber into proximity to the lower end of the spinneret .6. A heating pipe 20 extends some distance along the inside of the pipe 1'7 and thence into the jacket 2, as indicated at 21. An. outlet pipe 22 for the heating fluid extends from the upper portion of the jacket 2.

In the modification shown in Figs. '7 to 10, two cells or chambers are shown spaced apart and having their walls connected by a chamber or housing made up of plates 23. An inlet 24 is provided near the lower end of each cell into the lower portion of the housing, and corresponding outlets 25 are provided at the upper portion, so that the hot air or gases rising in this housing impinge against the sides of the filaments as they emerge from the spinnerets 6. A U-shaped pipe 26 for the hot fluid for heating the chamber between the cells extends longitudinally through the chamber.

In each one of the illustrated devices, air or gas is heated to a temperature above the tempera ture of the main body of the air. or gas in the cell so as to produce an upwardly rising jet or current of air or gas that strikes against the sides of the filaments, thus producing the desired effect, both because of the physical contact of the air or gas against the filaments and also bee cause this air or gas is at a higher temperature.

subjecting the filaments issuing from the spinnerets to the hot lateral air currents, as described above, causes them to assume irregular shapes.

in cross-section during the hardening thereof. The lateral current or deflection of gas so affects the evaporation of the solvent from the filaments during the formative and hardening steps that, instead of contracting regularly and uniformly to form round filaments or filaments with a dumbbell cross-section, they contract irregularly to form filaments of cross-sections such that the light is partially reflected, but is largely diffused by the surfaces of the filaments, with the result that the yarn and fabrics produced from such filaments do not have the high luster of ordi.

was

' for distorting the rayon filament surface which comprises extruding a spinning solution as a filament into a solvent-evaporating gas at a suitable temperature and subjecting the filament in the extrusion zone to lateral pressure of a gas at a higher temperature than the main body of evaporating gas in said zone, said lateral pressure being unequal around the periphery of the filament in said zone.

2. In the manufacture of rayon the process for distorting the rayon filament surface which comprises extruding a spinning solution as a filament into a solvent-evaporating gas at a suitable temperature in a zone secluded from the outside air and introducing laterally into said zone along a restricted part of the periphery thereof a transverse current of solvent-evaporating gas heated to a higher temperature than the main body of evaporating gas in said zone.

3. In the manufacture of rayon the process for distorting the rayon filament which comprises extruding a spinning solution as a filament into a solvent-evaporating gas at a suitable temperature and directing against a side of the filament while in plastic condition a current of gas at a higher temperature than the main body of evapcrating gas.

4. In the manufacture of rayon the process for distorting the rayon filament which comprises extruding a spinning solution as a filament into a solvent-evaporating gas heated-to a suitable temperature and subjecting the filament while plastic to the lateral impact of a unidirectional current of solvent-evaporating gas heated to a higher temperature than the main body of evap: crating gas.

5. In the manufacture of rayon the process for distorting the rayon filament surface which comprises extruding a spinning solution as a filament into a solvent-evaporating gas, producing an upward current of heated gas by heating such gas in a vertically extending passage and directing said current laterally against one side of the filament.

6. Apparatus for dry spinning rayon filaments including a spinning cell, a spinneret, a passage for heated gas and a nozzle at the end of said passage positioned at one side of the cell to direct a current of said gas across the cell against 120 one side of the filament while the latter is in a plastic state.

7. Apparatus for dry spinning rayon filaments including a spinning cell, a spinneret, an upwardly extending passage for heated gas having an outlet positioned at one side of the cell for projecting heated gas against a side of the filament while the latter is in a plastic state, and means for heating gas in the passage.

8. Apparatus as set forth in claim 7 in which 130 the heating means extends into the passage.

9. Apparatus as set forth in claim 7 in which the inlet to said passage opens into the cell.

10. Apparatus as set forth in claim 7 in which the passage is located within the cell.

11. Apparatus for dry spinning rayon filaments including a spinning cell, a spinneret, a passage for heated solvent-evaporating gas having an outlet in the cell positioned to direct a current of said gas across the path of the filament while 140 the latter is in a plastic state, and common heat-- ing means for said passage and cell.

ERNESTO ORIOLI. 

